It was previously reported that in healthy RMs, the relative frequencies of B-cell subsets differed substantially from blood to peripheral LNs, and upon infection, a significant decrease in the frequency of naive B cells from peripheral LNs is compensated by an increase in CD27+ memory B cells.74 In MLNs, no major changes were observed in the distribution of B-cell subsets during the acute phase of infection (Fig. 5b). Here, CD27 is linked to infection.